In industrial and commercial activity relatively dense particulate or viscous sedimentary waste material, such as sawdust, gravel, oil and the like, is often produced. Not only is it undesirable, and usually impermissible, to eliminate such waste material by discharging it into an ordinary public sewage system because it tends to obstruct such a system, but such material can often be put to a useful purpose such as, for example, improving the surface of a roadway. However, the removal of such dense, particulate or viscous sedimentary material, the transport of it to a desired location and the spreading of it over a predetermined surface area has heretofore been somewhat impractical due to the difficulties of removal of sedimentary material from a storage container to an intermediate container for transport, and thereafter removal of such material from the intermediate container and controllably spreading the material uniformly over a predetermined area.
Although apparatus for removing waste materials and transporting them to another location have previously been known, none is able entirely to overcome the aforementioned difficulties such that removal and useful application of such sedimentary waste material can be accomplished effectively. For example, Rupp U.S. Pat. No. 2,638,224 discloses an apparatus for cleansing septic tanks which utilizes a portable holding tank and an impeller-type pump for removing sewage from a septic tank to the holding tank and later discharging it at a predetermined location. However, a pump apparatus such as that disclosed in Rupp which requires the pumped material to flow through the impeller is unsuitable for dense, particulate or viscous waste material since that material would tend to damage the pump. Also, such dense, sedimentary material would settle at the bottom of the tank disclosed in Rupp and thereby be difficult to remove, and no provision is made for controlled, uniform spreading of the material when it is discharged.
Jurdye U.S. Pat. No. 3,544,010, directed to a mobile drum for distributing and spraying liquid manure, discloses a vacuum-type pump arrangement that does not require the pumped material to flow through the pump apparatus, which is more suitable for dense, sedimentary waste material, and means for spreading liquid manure over a wide surface area. However, dense, particulate or very viscous material would settle to the bottom of the Jurdye tank from which it would be difficult to remove, and the fan-like discharge apparatus of Jurdye is limited in its ability to spread such material uniformly over a predetermined surface area.
One type of tank mechanism which facilitates the emptying of dense, particulate or highly viscous sedimentary material therefrom is a rotatably mounted tank which enables material at the bottom of the tank to be entirely discharged through an opening in the side of the tank when the tank is rotated such that that opening is downwardly-oriented. Such mechanisms are disclosed, for example, by Clark U.S. Pat. No. 513,881, Murphy U.S. Pat. No. 743,312, Burnett U.S. Pat. 2,420,121, Burton U.S. Pat. No. 1,573,372, and Lutz U.S. Pat. No. 1,651,138. Although each of the rotatable tanks disclosed in the aforementioned patents is mounted upon wheels for mobility, each is also mounted such that its axis of rotation is perpendicular to the axes of rotation of its wheels so that dumping is accomplished only to the side of the apparatus, thereby eliminating any effective spreading function. Moreover, all of the tanks are mere hoppers, in the sense that they must be filled by some external means, and none appears to be suitable for evacuation as is necessary for a vacuum-type of pump arrangement that is desirable to remove dense, particulate or highly viscous material without that material flowing through the pump itself. While Burton and Lutz, in particular, disclose fixed-location, removable covers for closing an opening in such a rotatably-mounted tank, none of the covers appears suitable for providing a strong air-tight seal as would be desirable for use of such a tank with a vacuum-type pump.
Accordingly, there is a need for an improved portable apparatus for removing relatively dense, particulate or highly viscous sedimentary material from a storage container, transporting it to a desired location, and controllably spreading it uniformly over a surface area. Such an apparatus should utilize a pump mechanism for removing that material from the storage container to a portable tank without damage to the pump mechanism. Moreover the apparatus should permit complete discharge of such material, and enable the material to be controllably discharged and uniformly spread over a predetermined surface area.